Chevrolet 2002 S10 Pickup Owner's Manual page 76

When a new vehicle is delivered, the dealer provides the
owner with a pair of identical keys and a key code
number.
The key code number tells your dealer or a qualified
locksmith how to make extra keys. Keep this number in
a safe place. If you lose your keys, you'll be able to have
new ones made easily using this number. Your dealer
should also have this number.
2-6
This vehicle has one
-
double sided key for the
ignition and door locks. It
will fit with either side up.
NOTICE:
Your vehicle has a number of features that can
help prevent theft. But you can have a lot of
trouble getting into your vehicle if you ever
lock your keys inside. You may even have to
damage your vehicle to get in. So be sure you
have extra keys.
If you ever do get locked out of your vehicle call the
GM Roadside Assistance Center. See "Roadside
Assistance Center" in the Index for more information.